Chapter 1. Admin Guide

1.1. Overview

The time needed when writing a new OpenSIPS module
unfortunately is quite high, while the options provided by the
configuration file are limited to the features implemented in
the modules.

With this Lua module, you can easily implement your own
OpenSIPS extensions in Lua.

1.2. Installing the module

This Lua module is loaded in opensips.cfg (just like all the
other modules) with loadmodule("/path/to/lua.so");.

For the Lua module to compile, you need a recent version of
Lua (tested with 5.1) linked dynamically. The default version
of your favorite Linux distribution should work fine.

1.3. Using the module

With the Lua module, you can access to lua function on the
OpenSIPS side. You need to define a file to load and call
a function from it. Write a function "mongo_alias" and then
write in your opensips.cfg

...
if (lua_exec("mongo_alias")) {
...
}
...

On the Lua side, you have access to opensips functions and
variables (AVP, pseudoVar, ...). Read the documentation below
for further informations.

1.4. Dependencies

1.4.1. OpenSIPS Modules

None ;-)

1.4.2. External Libraries or Applications

The following libraries or applications must be installed
before running OpenSIPS with this module loaded:

Lua 5.1.x or later

memcache

This module has been developed and tested with Lua 5.1.?, but
should work with any 5.1.x release. Earlier versions do not work.

On current Debian systems, at least the following packages
should be installed:

lua5.1

liblua5.1-0-dev

libmemcache-dev

libmysqlclient-dev

It was reported that other Debian-style distributions (such as Ubuntu) need the same packages.

On OpenBSD systems, at least the following packages should be
installed:

Lua

1.5. Exported Parameters

1.5.1. luafilename (string)

This is the file name of your script. This may be set once
only, but it may include an arbitary number of functions and
"use" as many Lua module as necessary.

The default value is "/etc/opensips/opensips.lua"

Example 1.1. Set luafilename parameter

...
modparam("lua", "luafilename", "/etc/opensips/opensips.lua")
...

1.5.2. lua_auto_reload (int)

Define this value to 1 if you want to reload automatically
the lua script.
Disabled by default.

1.5.3. warn_missing_free_fixup (int)

When you call a function via moduleFunc() you could have a memleak.
Enable this warns you when you're doing it.
Enabled by default.

1.5.4. lua_allocator (string)

Change the default memory allocator for the lua module.
Possible values are :

opensips (default)

malloc

1.5.5. lua_user_debug (int)

Disable by default

1.6. Exported Functions

1.6.1. lua_exec(func, [param])

Calls a Lua function with passing it the current SIP message.
This function can be used from REQUEST_ROUTE, FAILURE_ROUTE,
ONREPLY_ROUTE and BRANCH_ROUTE.

Example 1.2. lua_exec() usage

...
if (lua_exec("mongo_alias")) {
...
}
...

1.6.2. lua_meminfo()

Logs informations about memory.

Chapter 2. OpenSIPS Lua API

2.1. Available functions

This module provides access to a limited number of OpenSIPS
core functions.

2.1.1. xdbg(message)

An alias for xlog(DBG, message)

2.1.2. xlog([level],message)

Logs the message with OpenSIPS's logging facility. The logging
level is one of the following:

ALERT

CRIT

ERR

WARN

NOTICE

INFO

DBG

2.1.3. setUserDebug

Enable or disable the xlog feature.
Disabled, the xlog function has no effect.

2.1.4. WarnMissingFreeFixup

Dynamically change the variable warn_missing_free_fixup.

2.1.5. getpid

Returns the current pid.

2.1.6. getmem

Returns a table with the size of allocated memory and the fragmentation.